c#学习之TXT文件的读取与写入

TXT文件读取

1.使用File类

using System;
using System.Windows.Forms;
using System.IO;
using System.Text;

namespace txtfile
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        //读取文件
        private void button2_Click(object sender, EventArgs e)
        {
            //全部读取1
            string str = File.ReadAllText(textBox1.Text, Encoding.Default);
            textBox2.AppendText(str + "\n");  

            //全部读取2
            string[] str1 = File.ReadAllLines(textBox1.Text, Encoding.Default);
            //遍历方式1
            foreach(string r in str1)
            {
                textBox2.AppendText(r + "\n");
            }
            //遍历方式2
            /*
            for (int i = 0;i<str1.Length ; i++)
            {
                textBox2.AppendText(str1[i] + "\n");
            }
            */   
        }
    }
}

 

2.使用StreamReader类

using System;
using System.Windows.Forms;
using System.IO;
using System.Text;

namespace txtfile
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        //读取文件
        private void button2_Click(object sender, EventArgs e)
        {
            //全部读取
            FileStream fs = new FileStream(textBox1.Text, FileMode.Open);
            StreamReader sr = new StreamReader(fs, Encoding.Default);
            string str = sr.ReadToEnd();

            //逐行读取
            string str1;
            while((str1 = sr.ReadLine()) != null)
            {
                textBox2.AppendText(str + "\n");
            }

            fs.Close();
            sr.Close();

        }
    }
}

---

TXT文件写入

1.使用FileStream类

using System;
using System.Windows.Forms;
using System.IO;
using System.Text;

namespace txtfile
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        //文件写入
        private void button3_Click(object sender, EventArgs e)
        {
            FileStream fs = new FileStream("D:\\test2.txt", FileMode.OpenOrCreate);
            byte[] data = Encoding.Default.GetBytes("你好！Hello World!");
            fs.Write(data, 0, data.Length);
            fs.Flush();
            fs.Close();

        }
    }
}

2.使用StreamWriter类

​
using System;
using System.Windows.Forms;
using System.IO;
using System.Text;

namespace txtfile
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        //文件写入
        private void button3_Click(object sender, EventArgs e)
        {
            FileStream fs = new FileStream("D:\\test2.txt", FileMode.OpenOrCreate);
            StreamWriter sw = new StreamWriter(fs, Encoding.Default);
            sw.Write("你好！Hello World!");
            sw.Flush();
            sw.Close();
            fs.Close();

        }
    }
}

​